Spin-dependent Transport in Periodical Magnetic Heterostructures

The propagation of particles with a half spin is considered in a system consisting of finite number of periodically repeating strongly magnetized barriers separated by nonmagnetic quantum wells. Such model quite well describes the transport properties of some thin-film heterostructures formed by periodically alternating magnetic and nonmagnetic layers of nanotubes. It is assumed that the vectors of the internal fields of barriers are parallel, and the internal field of one barrier is not coplanar with respect to the others. Thus, in a one-dimensional "ferromagnetic" system there is a noncoplanar "defect", the presence of which leads to two-channel scattering of particles-without a spin flip and with its flip. This significantly affects the transport properties of the system, in particular, the spin polarization of the scattered waves turns out to depend not only on the degrees of freedom describing the noncoplanarity of the "defect", but also on its coordinate.